DE1084437B - Process for obtaining a red dye from Penicillium purpurogenum - Google Patents

Description

Zierfahren to obtain a red dye from Penicillium purpurogenum It is known that in the course of its growth the mycelium of Penicillium purpurogenum turns red and that then by extraction with organic solvents from it a dye "purpurogenon" can be isolated, for which the formula of a dihydroxy-chromanobenzoquinone proposed (Roberts and Warren, J. Chem. S oc., London, 1955, p. 2992 ff.).

The fungus used various methods to obtain this dye acidic culture media - with a pH of around 4 (B r e n n e r, Svensk Botanisk Tidskr. 12 [1918], p.92; Raulin-Thom, Biochem. Journ., 59 [1955], P. 480). In this way it was possible to grow 250 g of mycelium on 701 nutrient solution from which 21 mg of purpurogenon could be isolated.

The invention relates to a method for obtaining a red dye from Penicillium purpurogenum in considerably larger yields, since the dye is used for larger part is contained in the nutrient solution, which makes its processing essential is simplified. This is achieved by using a substrate in which the dye is soluble. It is then in front of the mycelium running against the substrate given up and constantly being re-formed. In the same time the fungus then forms about 500 to 700 times more dye.

For the implementation of the method are suitable nutrient solutions, their pH at the start of cultivation is between 6 and 7.5; because in the course of growth if the pg shifts to the acidic side, it is advantageous in itself to be more familiar Way by adding a buffer or by repeatedly adding a basic one Do not let the pH drop below 5 by means of this. As a buffer it has become a common one Phosphate buffer proven; K H C 03 solution proved to be well suited as a basic additive. The culture is harvested after about 18 to 21 days; the majority of the dye is then in the deep red colored solution, from which this is known in Way, e.g. B. is obtained by extraction with butanol and subsequent purification. The yield is about 150 to 200 mg per liter.

The following facts can be used to interpret the processes involved serve: the dye is insoluble in acid. He can access an acidic nutrient medium from Mushrooms are not released, it accumulates in the mycelium, and this soon sets in further production. Because of the metabolism of the fungus there are always acids are formed, the same state occurs after a short time even if an initially neutral substrate is assumed. However, if you prevent the If the nutrient solution becomes more acidic, the mycelium can continuously release the dye and be formed anew. The dye obtained in this way is unique in its properties partly different from those given for Purpurogenon; so they stayed in the Color reactions with Fe C 13, NaOH and H2 S 04 described in the literature, as well the precipitation with K O H. Even the infrared spectrum cannot be used to identify an identity close with dihydroxy-chromano-benzoquinone. Except for the differences already mentioned the new dye turns out to be in contrast to the usual reducing agents constant to purpurogenon. It was hydrogenated in glacial acetic acid with platinum oxide no hydrogen consumed for 48 hours. The red color also disappears not when heating the alkaline solution with zinc dust, while Purpurogenon does this treatment is decolorized. In pharmacological studies it was found the dye according to the invention as completely non-toxic, it is therefore used for coloring Particularly suitable for foodstuffs as well as pharmaceutical and cosmic preparations. The following examples are intended to make the process according to the invention clear, without to limit it.

Example 1 A nutrient solution consisting of 1200 g molasses, 320 g malt extract, 100 ccm 10% K3 P 04 solution, 200 ccm 10% Nag N 0 solution, 20 g peptone, 320 g yeast extract is made up to 31 with tap water and sterilized. Respectively 50 ccm of this solution are diluted to 600 ccm, filled into 1-1 flasks and 1- Sterilized up to 2 times at 1 atm for 30 minutes. This substrate is made with a stock culture inoculated by Penicillium purpurogenum Stoll and incubated at 30 ° C.

After 21 days, the blood-red solution is filtered off from the mycelium and extracted with butanol. To washing with acidified water the alcohol is distilled off and the red dye is dried. * here yields 4bQ 190 mg per liter.

Example 2 A nutrient solution made from 1200 g molasses, 100 ccm 10% K3 P 04 solution, 200 ccm 10% Nag N 03 solution, 200 g corn spring water thickener made up to 3 l with tap water and sterilized. As in example 1, this Stock solution is diluted and sterilized, then mixed with a stock culture of Penicillium purpurogenum Stoll inoculated and incubated at 30 ° C. After 10 to 14 days a closed green mycelium cover is formed, then the dye starts to form, while the p $ sinks. Adding potassium bicarbonate to completion the pH was kept at at least 6 during the experiment. After 20 days it will be accordingly Example 1 worked up. The yield is about 180 mg per liter.

Claims (1)

Claim: method for obtaining a red dye from Penicillium purpurogenum by cultivating the microorganism on nutrient solutions, characterized in that the pH of the nutrient solution is initially set between 6 and 7.5 and it is expedient to adjust it during cultivation by adding a buffer solution or several times Addition of a basic substance to at least 5, whereupon, after a culture period of 18 to 21 days, the dye is obtained by extraction with butanol.